Mask



1952 H. P. BRADLEY MASK Filed Sept. 20 1951 Patented Nov. 25, 1952 UNITED STATES PATENT OFFICE MASK Holley P. Bradley, Tulsa, Okla.

Application September 20, 1951, Serial No. 247,416

3 Claims. 1 The invention relates to industrial masks and gas masks and has for its object to provide an auxiliary safety device attachable to the exhalation valve of the mask and terminating vat its outer end in a second exhalation valve, said extension having a chamber between the two valves in which chamber the exhaled air is trapped intermittently during a breathing operation, and intermittently discharged to the atmosphere, thereby allowing the warm air within the chamber of the extension to keep the inner valve comparatively warm for preventin freezing of the valve carried by the face piece.

A further object is to provide the inner and outer ends of the extension with in-turned annular flanges receivable within annular channels of the valves, said valvesbeing formed from a' flexible material, for instance rubber.

With the above and other objects in view the invention resides in the combination and arrangement for parts as hereinafter set forth, shown in the drawing, described and claimed, it being understood' that changes in the precise embodiment of the invention may be made within the scope of what is claimed without departing from the spirit of the invention.

In the drawing:

Figure 1 is a perspective view of the extension, part being broken away to better show the structure.

Figure 2 is a vertical longitudinal sectional view through the extension and a portion of the face plate.

Figure 3 is a perspective view of the mask, showing the mask in position for use.

Referring to the drawing, the numeral l designates the face piece, which is of conventional construction, and adapted to snugly fit the face of the user. Connected to the face piece I adjacent its lower end is a breather tube 2 which leads to a purifying canister 3. It will be understood that the purified air may be supplied to the mask in any suitable manner, for instance on an air line or in connection with abrasive masks.

Heretofore when a single exhalation valve is used, which valve is exposed to the atmosphere, and particularly to low temperatures, there is danger of the valve freezing, and the present device is primarily designed to overcome this difficulty, and comprises the use of an inner valve 4 and an outer valve 5. Both valves are of similar construction, and in Figure 2 one valve is shown, in side elevation and one in transverse cross. section. The inner valve 4 is carried by an apertured annular ring 6 having an annular channel I in its outer periphery. Channel 1 forms spaced ribs 8, and as the valves 4 and 5, as well as their rings 6, are formed from rubber, they may be deformed and snapped into the mask opening 9, and also into the annular opening l0 formed by the annular flange l I at the outer end of the extension member l2. The inner end of the extension member l2 is provided with an inturned annular flange l3, which flange extends into the annular channel I of the inner valve ring 6, therefore it will be seen that the extension can be attached to the inner conventional valve without modifyin the construction thereof.

Extension member I2 is provided with an air trap chamber l4, and in which chamber part of the exhaled warm air is trapped during a breathing operation, thereby maintaining the inner valve 4 above a freezing temperature. As the exhaled air passes into the chamber M the air flexes the valve 4 to the dotted line position shown in Figure 2, and simultaneously previously trapped air in the chamber l4 flexes the valve 5 outwardly for discharge to the atmosphere, therefore it will be seen that the air in the chamber I4 is intermittently changed, but a sufficient amount of the warm air is trapped for preventing freezing and sticking of the valve 4 incident to sweating and the like. Another advantage of the double valve, it is double insurance against leakage inwardly, particularly when working in the presence of gas. It will be noted that the annular channel 1 in the outer ring 6 is of the same width as that of the inner ring, hence it will be seen that the valves and valve bodies are interchangeable.

The valves 4 and 5 are provided with integral rubber headed members I5 which can be forced through the apertures l6 of the rings 6. i

From the above it will be seen that a gas mask extension member is provided which will trap a portion of the exhaled air, and allow the exhaled air to be utilized for maintaining the inner valve at a temperature above freezing at all times.

In some cases the outer valve may be eliminated, and the inner valve used.

The invention having been set forth what is claimed as new and useful is:

1. The combination with a respirator mask, a face p1ece carried by said mask, a channeled valve ring mounted in an opening of the face piece, the flanges of said channeled ring extending outwardly, one of said flanges engaging the inner side of the face piece, the other flange of said ring being spaced outwardly from the face piece, a

valve carried by the outer side of the ring, a chambered extension member supported by the ring, said extension member having an inwardly extending annular flange at its inner end engaging over the outer flange of the ring and extending into the channel of the ring, a channeled ring mounted in the outer end of the extension, an inwardly extending annular flange carried by the outer end of the extension and extending into the channel of the last named ring and a valve carried by the outer side of the last named ring,

2. A device as set forth in claim 1 wherein the inner and outer annular rings are similarly shaped.

3. A device as set forth in claim 1 wherein the rings and valves are formed from a deformable material.

I-IOLLEY P. BRADLEY.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 428,611 Hurd May 27, 1890 2,326,651 Husted Aug. 10, 1943 

